Engine



June 20, 1939. R. K. LEE ,8

ENGINE Filed Feb. 13, 1936 8 Sheets-Sheet 1 IN VEN TOR.

F0562 lee.

/8 BY y r I fl ATTORNEYS.

June 20, 1939. R, K E I 2,162,817

ENGINE Filed Feb. 13, 1936 8 Sheets-Sheet 2 11v VENTOR F0562" 4 ea.

J ne'zo, 1939.

R. K. LEE

ENGINE Filed Feb. 15, 1936 s Sheets-Sheet s Foyer BY ATTORNEYS.

INVENTOR. Klee.

RJKILEE June 20, 1939.

ENGINE 'Filed Feb. 13, 1936 8 Sheets-Sheet 4 INVENTOR. Foyer lee.

' June20,1939. LEE 2,162,817

ENGINE Fil ed Feb. 13, 1936 s Sheets-Sheet 5 INVENTOR. Foyer /1f l e- ATTORNEYS.

R. K. LEE

ENGINE Filed Feb. 13 1956 8 Sheets-Sheet 6 INVENTOR.

Wager/188.

ATTORNEYS.

June 20, 1939.

R, K. LEE

ENGINE Filed Feb. 13, 1956 8 Sheets-Sheet 7 ATTORNEYS.

June 20, 1939; R K, LEE 2,162,817

ENGINE Filed Feb. 13, 1936 8 Sheets-Sheet 8 INVENTOR. Eager l2. lee.

ELLE. I

ATTORNEYS.

they are particularly adapted to such applica- Patented June 20, 1939 UNlTED STATES PATENT OFFICE ENGINE Application February 13, 1936, Serial No. 63,697

19 Claims.

This invention relates to internal combustion engines and refers more particularly to improvements in engines of the type wherein the cylinders are arranged radially about the engine crankshaft. My inventicn is also particularly related to internal combustion engines of the positive valve operating type although in the broader aspects thereof many of the novel features of my invention are not necessarily limited to radial types of engines or to engines having positively operated valves.

It is an object of my invention to provide an improved valve operating mechanism which may be successfully operated at speeds materially higher than the usual speeds of conventional engines used for driving motor vehicles, for example. While my improvements are not necessarily limited in their application to such high speed engines or to engines for driving motor vehicles,

tions.

Another object of my invention is to provide improved valve operating means for radial engines wherein the timing of the valve operations 'will be maintained with improved precision, thereby resulting in greater engine efficiency, smoother engine operation, and adaptability to relatively high engine speeds.

A further object of my invention is to provide an improved valve operating means especially adapted for radial engines wherein a plurality of valve operating shafts are cooperatively associated with each other and simultaneously driven in an improved manner from the engine.

Another object of my invention is to provide an improved valve operating mechanism, especially of the positive operating type, wherein the valve operating arms are arranged in an improved manner with respect to the engine cylinders and crankcase valve operating chamber. Thus, I have provided an improved arrangement and location of pairs or groups of valve operating arms adapted for operation by an improved and simplified arrangement of actuators. In this connection, one feature of my invention in a more specific phase resides in the provision of a plurality of camshafts, preferably the same in number as the number of engine cylinders radially arranged, pairs of cams on adjacent camshafts cooperating to positively actuate the engine valves and wherein a cam on each camshaft has a multiple function of valve control. In such manner, the number of cams necessary may be reduced and the valving mechanism simplified.

An additional object of my invention resides in the provision of improved means for driving a plurality of valve shafts wherein the crankshaft is free to deflect in an improved manner without adversely influencing the valve drive mechanism driven therefrom. This feature of my invention provides improvements especially in connection with engines having cantilever crank pins, my invention making it possible in an improved manner to utilize a crank pin of this type to drive the valve operating mechanism without influence from crank pin deflections.

A further object of my invention is to provide a lubricating means or system of improved efl'iciency and simplification for the valve operating shafts, valve driving mechanism, connecting rod bearings and other operating parts.

Another object of my invention is to provide improved means for operating the engine accessories, and for improved mounting and arranging the accessories especially for an engine of the radial cylinder type.

Afurther object of my invention is'to provide a simplified and efficient cooling system, especially for radial engines, such system preferably incorporating a combination of thermo-syphon and pressure circulation of the cooling medium.

Another object is to provide a simplified, lightweight engine structure of the radial cylinder positive valve operated type.

Among further features of my invention is the provision of a novel sub-assembly for the valve operating mechanism making for easier and less costly assembly and repair of the engine; an improved intake and exhaust manifolding system of increased efficiency and reduction in the weight and cost of the manifold arts; and improved means for mounting the connecting rods on the crankshaft drive pin whereby the bearing loads are distributed in an improved manner so that the size and weight of the connecting rods may be minimized.

Further objects and advantages of my invention will be more apparent from the following detailed description of one illustrative embodiment thereof, reference being had to the accompanying drawings, in which:

Fig. 1 is a sectional elevational view taken longitudinally through my engine. Fig. 1A is an enlarged view of the camshaft gearing as shown in Fig. 1.

Fig. 2 is a front elevational View of the engine with parts thereof broken away.

Fig. 3 is an enlarged detail View taken in cross section along the line 33 of Fig. 2.

Fig. 4 is a front sectional elevational view showing the valve operating mechanism, the view being taken along the line 44 of Fig. 1.

Fig. 5 is a somewhat diagrammatic sectional elevational view corresponding in general to Fig. 4 and illustrating a typical set of cams and associated levers for operating the valves of one of the engine cylinders.

Fig. 5A is a side elevational view showing, in enlarged and exaggerated form, a typical tappet and lever operating connection in the mid-portion of operation thereof.

Fig. 5B is a similar view with the parts shown in an extreme position of operation thereof.

Fig. 5C is a detail sectional view taken as indicated by the line 5C5C of Fig. 5.

Fig. 6 is a diagrammatic development of the valve operating lever shafts and illustrating the relative positions of the valve operating levers and engine cylinders associated therewith.

Fig. 7 is a diagrammatic development view showing the axial and lateral relationship of the valve operating cams.

Fig. 8 is a sectional elevational view taken along the line 88 of Fig. 1 and illustrating the valve operating drive from the cantilever crank pin.

Fig. 9 is a detail sectional view taken along the line 9-9 of Fig.8.

Fig. 9A is a modification of the construction shown in Fig. 9.

Fig. 10 is a sectional view showing the valve chamber casting, the section being taken as in- ,dicated by the line I0l0 of Fig. 13.

Fig. 11 is a sectional view showing the main crankcase and cylinder casting, the section being taken along the line IIH of Fig. 14.

Fig. 12 is a sectional elevational view through the line l2l2 of Fig. 1, showing a portion of the rear wall of the valve chamber casting.

Fig. 13 is a front elevational view of the valve chamber casting.

Fig. 14 is a front elevational view of the crankcase and cylinder casting.

Fig. 15 is a front elevational view of the intake manifold with parts thereof broken away to illustrate the fuel mixture distributing means.

Fig. 16 is a sectional view thereof taken along line !$-l6 of Fig. 15.

Fig. 17 is a detail sectional view along line ll-il of Fig. 15.

Fig. 18 is a detail plan view taken as indicated at !8-l8 on Fig. 15.

Fig. 19 is an end view of the Fig. 18 structure. Referring to the drawings, I have illustrated the various features of my invention in connection with a water cooled engine having the cylinders thereof disposed radially around the axis of the crankshaft although, as will presently be more apparent, many of the features of my invention are adapted for use in connection with other types of engines, compressors and the like. According to the present embodiment of my invention, the engine is formed of a main casting comprising a centrally disposed substantially cylindrical main crankcase portion 20 adapted to provide a chamber accommodating movement of the engine crank, this central portion 20 preferably integrally carrying the outwardly radiating cylinders 2! having communicating water circulating jackets 22 provided by the outer wall 23. For convenience of reference in my drawings and in the following description, the various cylinders of the engine may be referred to in their order of progression around the crankshaft as cylinders No. 1, No. 2, No. 3, No. 4, and No. 5. While I have illustrated my invention in connection with an engine having five radially arranged cyinders, it will be readily apparent that any desired number of cylinders may be employed, preferably three or more in number. The radial axes of the cylinders 2| are progressively offset longitudinally of the engine although the increment of the offset, in accordance with the teachings of my invention, is relatively small so that I am enabled to minimize the length of the engine, the cost and weight thereof, together with minimizing the weights of the reciprocated parts and a consequent lessening of the bearing loads resulting from the normal operation of the working parts.

Operating within each cylinder 2| is a piston 29 articulated by a wrist pin 25 to the outer end of a connecting rod 26. The inner ends of the connecting rods have integral annular bearing portions 21 having their side faces in contact with each other whereby these bearing portions are successively spaced longitudinally of the engine in accordance with the increment of offset of the cylinders respectively associated therewith.

In order to minimize the weight of the connecting rods with resulting minimization of bearing loads, the connecting rod bearing portions 21 are preferably integral with the main connecting rod portion 26 or otherwise suitably formed so that they do not have the customary separate bearing caps with attendant fastening bolts and the like.

One feature of my invention resides in the provision of a novel bearing or journalling means between the connecting rods 26 and the engine crankshaft generally designated at 28. This crankshaft has a front anti-friction bearing 29 carried within a cylindrical opening 30 formed in the rear transversely extending crankcase Wall 3i, a bearing retainer ring 32 being secured to wall 3| by suitable fasteners 33, one of which is illustrated in Fig. 1.

The rear end of the crankshaft terminates in a hub 34 rotatably iournalled by a bearing 35 carried by a cover 36 which is secured by fasteners 37 to the crankshaft flywheel housing 38, the latter being fixed by fastening assemblies 39 to the bossed portions 40 projecting rearwardly from the aforesaid Wall 23.

The crankshaft 28 is thus journalled at the rear end of the engine by the front and rear bearings 29 and 35, the crankshaft carrying a hollow spindle 4i having its axis parallel to the axis of rotation of the crankshaft but disposed eccentrically thereto. This spindle is rotatably journalled in the crankshaft by the front and rear anti-friction bearing assemblies M and 42, respectively, so that the spindle may rotate about its axis independently of the rotation of the crankshaft although the spindle will, of course, at the same time rotate with the crankshaft about the axis of rotation of the latter. It will be noted that the front crankshaft bearing 29 is disposed intermediate the spindle bearings M and 12 so that the spindle extends within the crankshaft bearing 29.

The spindle 4! has a crankpin forming projection 43 thereof extending into the main crankcas 20 for mounting the connecting rod bearing portions 21'. Intermediate the crankpin 43 and each connecting rod bearing 21 I have provided a bushing 44 and, according to one feature of my invention, each of these bushings is free from its associated connecting rod and crank pin so that it is capable of rotation relative to bothof these, members. By reason of such bushing means together with the rotatable mounting of spindle 4| in crankshaft 28, the spindle 4| and its crankpin portion 43 is free to instantaneously rotate with any one of the connecting rod bearings 2'1 and the bushing 44 associated therewith depending on which connecting rod is exerting the greatest instantaneous pressure on the crankpin. During the operation of the engine, the cylinders are progressively fired in a well-known manner so that the pistons 24 successively operate through their respective connecting rods 26 to rotate the crankshaft 28 through the intermediary of .the

crankpin 43. It will thus be apparent that the connecting rods successively exert their thrusts or pressures on the crankpin in the order of the firing of the engine, which, for example, may be l352--4--1. By arranging the various bushings 44 capable of rotation relative to the crankpin and the connecting rod bearing 2'! associated therewith, the crankpin ,may successively rotate with each connecting rod bearing and bushing assembly and in this manner the bearing load at such connecting rod bearing may be greatly minimized. This bearing load is known to be a product of the pressure exerted on a crankpin times the velocity of the relatively moving bearing parts, and by reason of my invention this factor is greatly reduced by reason of the minimization of the relative velocities of the bearing parts, Furthermore, the bearing load is distributed both within and without the cylindrical bearing surfaces of each of the bushings 44 thereby still further distributing the bearing loads to these locations.

In the present embodiment of my invention the crankshaft 28 has a flywheel portion 45 adapted to house a clutch for transmitting the drive to the power take-off driven shaft 46. Briefly, this clutch comprises a driving pressure plate 4! cooperatingwith the crankshaft flywheel part 48 to drive a clutch disc 49 mounted on shaft 46, the pressure plate being released against the action of its springs 53 through the intermediary of the release levers 5| and pin 52. The levers 5! may be actuated in any suitable manner as, for

example, through ,the thrust shaft 53 as more particularly described in my aforesaid co-pending application. The crankshaft 28 is preferably provided with a counterweighting portion 54 disposed diametrically opposite the spindle 4! for counterweighting the reciprocating parts acting on the spindle as well as the spindle itself. Inasmuch as it is not possible ,to locate the counterweight 53 directly opposite the resultant of the spindle forces, a couple is set up longitudinally of the crankshaft and in order to provide a neutralizing couple, the crankshaft flywheel 45 is preferably counterweighted at 55 diametrically opposite to the center of mass of the counterweight 54.

Adjacent the upper end of each cylinder 2i there is provided a forwardly extending intake conducting passage 56 controlled by an intake valve 5.7 having its valve stem 58 extending through the guide way 58. A similar valve 5% is adapted to control an exhaust passage 69 (see 3) which extends laterally or to the side of each cylinder for conducting the exhaust gases from each cylinder through a branch conduit M of the annular exhaust manifold 62 mounted at the rear of the engine around the crankshaft housing 38.

The intake and exhaust valves are respectively guided at their lower ends by the tappet guides 63 and 64, these valvesb'eing respectively connected to the intake and exhaust valvetappets 65 and 66 respectively slidable in the guides, 63 and 64; The inner end of each tappet is pro-- vided with a spool portion 61 for actuation by a belicrank lever as will presently be more apparent.

The various pairs of tappet guides 63 and 64 are formed as a part of a chest or chamber casting 68 which forms a forward extension of the crankcase structure and which is adapted to provide a separate bench sub-assembly capable of attachment to the main crankcase casting hereinafter described in more detail,

The chamber casting 68 has a reartransverse wall G9 which separates the valve operating chamamong other things, provides a front closure for the valve operating chamber 10. Located within the chamber ii) are a plurality of valve operating shafts 13, 14, 15, 'IB and 11 respectively assoslated with cylinders No. 1 to No. 5, the number of valve operating cam shafts preferably corresponding to the number of cylinders 2| of the engine. The valve shafts have their axes parallel to the axis of rotation of the crankshaft 28 and are located at equal distances from this axisjoeing spaced circumferentially from each other to accommodate the cam followers as will presently be more apparent. The rear end of each valve shaft is rotatably jo-urnalled by a bearing 78 carried by the wall 39, the forward ends of the valve shafts being rotatably journalled by a bearing 19 carried by the front wall 12. A driving shaft 80 extends forwardly of the crankshaft 28 and is rotatably journalled by the front and rear bearings 8i and 82 respectively carried by the walls l and 69. v

The shaft 80 is adapted to be driven in a novel manner from the crank pin 43 and to this end, shaft 80 has its rear end formed withthe annular driving disc 83 disposed rearwardly adjacent wall 69, this disc having a rearwardly extending lug or crank 84 telescoped within the forwardly extending end of crankpin 43 as best shown in Figs. 1, 8 and 9.

The crank is provided with a pair of diametrically opposite roller receiving grooves or pockets 85 each of which receives a cylindrical roller 86, these rollers being disposed circumferentially of the axis of rotation of crankshaft 28 so that they provide an anti-friction roller driving connection between crank pin 43 and disc crank or pin 84. There is preferably only a very small amount of clearance in the direction of drive between crankpin 43 and crank 84 so that the crankpin is adapted to drive shaft 80 with substantially no lost motion. However, a relatively large amount of clearance 8! is provided between crankpin 43 and crank 84 in the radial direction. By reason of such arrangement the cantilever crankpin 43 is free to deflect without binding'at crank 84 and without loading the bearings of shaft tions of the crankpin, the rollers 85, readily ac- The forward end of casting 68 terminates in an outwardly extending annular flange H to, which is secured the forward transverse wall 72 which,

commodate the relative movement between the crankpin and crank 8 1.

It will be observed that the spindle bearing II is formed of rollers running onbushing l I Heretofore, in connection with engines having rotatable cantilever crank pins, I have employed a single series of rollers at this front bearing location but have experienced difficulties in such arrangement owing to the inherent crank pin deflections loading the front edges of the rollers. This tilting of the crank pin spindle thus produces high loading and wear at the front spindle bearing. By providing the double row of rollers I have found that this difficulty is eliminated by relieving the high pressures at the front edges of the rollers. In this connection a modified arrangement illustrated in Fig. 9A still further accommodates the crank pin deflections without unduly loading the bearings. In this construction which may be substituted for the Fig. 1 arrangement the only difference resides in forming the bushing 4 I with undercuts M providing clearance with the spindle for accommodating the tilting and to form the relatively thin edges ti which deflect under spindle tilting to relieve the load on the edges of the rollers M The bushing M has a relatively small area seating on the spindle and may be a press fit thereon.

In order to drive the valve shafts in unison from shaft 89 and at half speed therewith for a four stroke cycle engine illustrated in the present embodiment of my invention, shaft 89 is provided at the rear of bearing ill with a driving pinion 88 meshing with a gear 89 of twice the diameter so that the reduction drive is obtained through this first gear drive. The gear 89 for convenience of manufacture is formed separately from valve shaft 76 on which this gear is mounted, suitable fasteners 99 securing the gear 89 to a smaller diameter gear 9| formed as a part of shaft I5. Gear 9I meshes with a gear 92 mounted on shaft 80 but freely rotatable relative thereto. Each remaining valve shaft has a gear 93 fixed therewith and meshing with the central gear 92. The various gears 9|, 92 and 93 are all of the same diameter and are arranged in a common plane transverse to the axis of rotation of the crankshaft; it being noted that by reason of my novel valve shaft driving arrangement, these gears may be placed in this common plane without interference with one another as shown for example in Fig. 4. In the event that the drive was taken directly from shaft 80 to the various valveshafts as a reduction drive, it would not be possible to arrange the valveshaft gears in a common plane without interference with one another especially where a relatively large number of engine cylinders is employed.

Each of the valve shafts or camshafts F3 to 'I'! has mounted thereon and fixed thereto a plurality of valve actuators, preferably cams, each cam cooperating with at least one of the cams on a valve shaft adjacent thereto for positively operatlng at least one cam follower, preferably in the form of a bell crank lever operably connected to one of the tappets 65 or 66. In the present embodiment of my invention, I have provided a novel arrangement whereby each valve shaft is provided with three cams one of which is a multiple purpose or a multiple function cam in that this particular cam cooperates with a cam on the two adjacent valveshafts in each circumferential direction from such multiple function cam whereby to operate a pair of the bell crank levers. In the particular illustrated embodiment of my invention, the common cam on each valve shaft is a closing cam for the intake and exhaust valves of the cylinder associated therewith, the two remaining cams on each valve shaft each being adapted for coaction with a cam on an adjacent valve shaft to perform the opening event in the cyclical valve operation for an intake and exhaust valve of adjacent cylinders. Inasmuch as I have illustrated an L-type of radial engine wherein the valves move outwardly to open, it is preferable to employ the common cam on each valve shaft as a closing cam rather than a common opening cam for each pair of levers. In the event that valves of the overhead type were employed, it would ordinarily be preferable to employ the common cam as an opening cam. The use of a common cam for a pair of levers depends somewhat upon the relation between the cam duration of lift and the interval between opening of the intake and exhaust valves. This relation should ordinarily be such that a satisfactory overlap should exist between the opening of intake and the closing of exhaust valves. This relation may be varied to accommodate a different number of cylinders, as for example by changing the length of the lever arms.

More specifically, according to the illustrated embodiment of my invention, and with particular reference to Figs. 4 to '7, the cams on the various valve shafts are arranged in a plurality of planes 9%, 95, 95, 9! and'96 illustrated in Fig. '7, these planes being parallel to each other, transverse to the axis of rotation of the crankshaft, and successively oifset by an increment corresponding to the increment of offset of cylinders 2I as hereinbefore referred to. In Fig. 5 I have illustrated a typical arrangement of cams which lie in the plane 95 for operating the intake and exhaust valves of cylinder No. 1. The common closing cam is designated at 99 on valve shaft I3 while cooperating therewith are intake and exhaust opening cams respectively carried on valve shafts I l and H for respectively opening the intake and exhaust valves of the No. 1 cylinder.

Extending longitudinally of the engine between the walls I59 and I2 are the circumferentially spaced shafts I92, I03, I04, I05 and I06 each being adapted to rockingly or pivotally support a pair of grouped bell crank levers I01 and I08. At each bell crank lever supporting shaft, the lever designated as It! is that lever which operates an intake valve while the associated lever I08 at each cylinder operates the exhaust valve. As best noted from the typical example of lever arrangement shown in Fig. 5, the levers I9! and IE8 for cylinder No. l are pivotally supported on adjacent supporting shafts, such as the shafts I62 and IE5 respectively. The lever III! is operated by the common closing cam 99 by reason of a generally radially inwardly extending arm. I09 terminating in a cam follower portion III) and a generally circumferentially extending arm III projecting toward the associated cylinder and valve shaft carrying such common cam, as the valve shaft I3 in the Fig. 5 illustration. The valve operating end of lever arm II I is formed at H2 for engaging the spool portion 61 of the intake tappet 65.

Each bell crank lever I08 has a similar inwardly extending arm IE3 and follower II 4; also a circumferentially extending arm II5 terminating in a tappet engaging forked end I I6 for operating an exhaust tappet 66. It will be noted, however, that at each bell crank lever supporting shaft, the armsI I I and .I I5.of each pair of levers I91 and I08, respectively, extend substantiallyin opposite directions circumferentially.

Referring to the typical valve shaft 13 by way of example, in addition to the common closing cam 99 this valve shaft also carries the opening cams M1 and H8 respectively acting through a lever I98 for effecting the opening of the exhaust valve associated with No. 2 cylinder, and for effecting the opening of the intake valve of the No. 5 cylinder by acting on a lever I01. .At valve shaft 11 the additional cams H1 and II8 respectively operate to open the exhaust valve of the No. 1 cylinder by a lever I08 and to open the intake valve of the No. 4 cylinder through a lever I01; cams H1 and H8 of 'valve shaft 16 respectively likewise operate to open the exhaust valve of the No. 5 cylinder and to open the intake valve of the No. 3 cylinder; the cams H1 and I I8 of valve shaft 15 respectively operate to open the exhaust valve of the No. 4 cylinder and to open the intake valve of the No. 2 cylinder; and the corresponding cams H1 and I I8 of valve shaft 1 3 respectively operate to open the exhaust valve of the No. 3 cylinder and to open the intake valve of the No. 1 cylinder. In order to properly position the various cams in the aforesaid planes, each valve shaft carries one or more spacers II9 except in the instance of valve shaft 16 where an accessory driving gear I29 takes the place of the spacers. FromFig. 6 it will also be noted that the bell crank levers are arranged in paired groups in association with each of the engine cylinders, the tappet actuating arms of the lever pairs at each cylinder being progressively offset longitudinally of the engine in increments corresponding to the increment of offset of the engine cylinders. In this manner the bell crank levers are arranged in pairs in the various planes 94 to 98 for the desired operation by the cams disposed in these planes. according to the typical illustration in Fig. 5.

In Fig. 1 I have illustrated a typical arrangement in connection with shaft I 94 for pivotally supporting a pair of the bell crank lever arms. This shaft is clamped between the end members I2I and I 22 respectively associated with the walls 69 and 12, by reason of the bolt assembly I23. A spacer l 24 positions the bell crank levers in the desired planes, it being understood that the spacers for the other lever supporting shafts are appropriately arranged for properly positioning the lever pairs in accordance with the diagrammatic illustration shown in Fig. 6.

Referring to Figs. 5A, 5B and 50 I have illustrated a construction which is typical of the operative connection between the various tappets and the bell crank lever arms connected thereto. Each spool portion 61 has its upper and lower lever arm engaging surfaces I25 and I26 formed as a part of a spherical surface. The lever arm end M6, for example, has a pair of surfaces I21 and I28 of approximately spherical shape to respectively engage surface I25 when the arm end 5 I6 is in its extreme inwardly and outwardly positions of swinging movement. The surfaces I21 and, I28 are separated by an intermediate surface region I29 which engages surface I25 when the arm end H5 is in its intermediate position I as illustrated in Fig. 5A.

For approximating the spherical surface condition of surfaces I21 and I23 as a practical mat-' ter for manufacturing conditions, each of these surfaces is formed as a combination of a longitudinally extending arcuate surface of the same radius of spherical surface I25 and, as ShOWn in Fig.- 5C, a similar surface generation transversely .to the forks of an arm end II6 on a radius the same as that forming spherical surface I25. The arcuate contour transversely to the arm end II6 extends throughout the length of the fork portions of this arm end so as to include the central zone I29.

The inner face of the arm end H6 is likewise formed with surface portions I21 I28 and I 29 which cooperate with spherical surface I26 of the tappet spool. Thus, when the arm end H6 is in its extreme outward position, surface I28 has a full area of en-gagement'with spherical surface I25 and surface I21 has a similar engagement with surface I26. Likewise, when the arm end II 6 is in its extreme inward position it will be apparent that surface I21 engages surface I25 and surface .I28 engages surface I 26.

By reason of the foregoing arrangement of contacting surfaces between the levers and tappets, it will be observed that I have provided a progressively increasing surface area contact between each lever and tappet as the tappet approaches either of its extereme positions of movement. This is of considerable importance inpreventing wear between the tappet and lever since I have provided a relatively large amount of bearing area at the times when the load is relatively great on the lever arm ends as when the load is a maximum on the levers. This load is, of course, greatest at the times when the direction of load of the tappets and valves is changed since the mass of such assembly must be brought to rest and then accelerated again in the opposite direction. During the intermediate point of movement of the tappets, the load is relatively small and the intermediate portions I29 and I29 will provide ample bearing areas, this area progressively increasing as the tappets and valves ap- ..proach both of the extreme positions in their remaining surfaces I21, I28, I21**, I28 and I26 7 preferably having the same radial dimension as aforesaid. I

It will furthermore be noted that each valve and its tappet is free to rotate for good seating and wear, the various spherical surfaces at the tappet spools and lever ends readily accommodating this rotative action.

One feature of my invention resides in the novel manner of attaching the cam chamber casting 68 to the main crankcase and cylinder block casting 20. Where the engine cylinders 2I are progressively offset longitudinally of the engine,

according to the illustrated embodiment of my invention, difiiculty has heretofore been experienced in providing a connection between the casting portions providing a seal between thev castings and where the connecting parts may be simply machined and secured together. The offsetting of the cylinders introduces a number of complications but particularly where the valve operating mechanism enclosed in casting 68 is adapted for'attachment for a subassembly according to the teachings of my invention. I have provided a novel construction of attaching the castings referred to, my attaching structure being of relatively simple construction and capable of quantity manufacture at relatively small cost.

It will be apparent that the various paired groups of tappet guides 63 and 64 are progressively offsetv longitudinally of the engine in accordancc With the progressively offsetting 'of the.

pair of bell crank levers and cam planes 94 to 98 as referred to above. The tappet guide 64 associated with each of the engine cylinders has a laterally and outwardly extending bracket I38 projecting integrally therefrom as best shown in Figs. 2, 3 and 13. At the outer end of each of these brackets I have provided a terminal lug I3I having an inclined machined face I32 adapted to seat on a corresponding face I33 of a bracket I34 (see Fig. 11) which extends inwardly integral with the outer wall 23 of each cylinder casting 2|. Each bracket I38 also has a shouldered portion I35 adapted for piloting engagement with a corresponding shoulder I35 of each cylinder bracket The surfaces I33 of the cylinder bracket I34 are machined simultaneously to lie in a common plane I31, the main casting 29 being rotated about an appropriate axis during the machining operation. The plane 131 is at such an inclination with the axis of the crankshaft 28 that it will dispose the pairs of tappet guides 53 and 64 in their proper positions Without the necessity of machining separate bracket faces in different planes and also for the purpose of obtaining an efficient seal for the two castings presently referred to in detail. The cylinder brackets I34 provide the support for the casting 38 by reason of the brackets I38, screw bolts I38 holding these brackets securely in engaged position.

The casting 68 is provided with an annular machined sealing surface I39 which is disposed in a plane parallel to the aforesaid plane I31. This sealing surface I39 engages a sealing gasket I40 illustrated in Fig. 1, the gasket in turn contacting with a similar sealing surface I4I also lying in a similarly inclined plane. The surface MI is machined around the inner edges of the cylinders 2|, it being noted that the inclination of the plane of surface I4I corresponds to the progressive offsetting of the various cylinders in a direction longitudinally of the engine. The crankcase casting 28 is provided with the opening I42 adapted to receive the machine portion I43 accommodating projection of the aforesaid wall 69 through the opening I42. The surfaces I42 and I43 are preferably machined at right angles to the surfaces MI and I 39 respectively, it being understood that the various inclined surfaces of each casting may be machined while each casting is rotated about appropriate axis. When the casting 58 is assembled to the crankcase casting 25, the inclined surface I43 preferably has a clearance with the surface of opening I42 so that the support of casting 58 is taken through the brackets I38 and fasteners I38.

The forwardly extending end of shaft 88 is rotatably supported by the aforesaid bearing 8| which is carried Within the cylindrical hub I44 which projects forwardly as a part of the valve chamber front wall 12. This wall 12 provides a boundary wall for the annular distributing portion I45 of the intake manifold which has outwardly extending branches I46 for distributing the intake fuel mixture to the respective supply conduits 56. The annular inner boundary wall of this manifold is provided by the hub I44. The central manifold portion I45 is adapted to be secured to the wall 12 by suitable fasteners I41, a shaft seal carrying plate I48 being secured by fasteners I49 to the manifold portion I45. Further details of the intake manifold structure will be referred to hereinafter.

Keyed at I58 to the forward end of shaft 80 is a hub II carrying the pulley I52 and the radiator cooling fan I53, the latter being mounted through the intermediary of the vibration damping rubber connection I54. The engine radiator is not illustrated although it may be of any known type preferably located as usual just forwardly of the cooling fan I53 for the water cooled type of engine illustrated.

I will now describe the novel driving arrangement and location of the various accessories for the engine. I have already referred to the novel location of the fan I53 at the forward end of the valve gear driving shaft 851. The pulley I52 is adapted to drive a belt I55 which operates a laterally disposed driven pulley I56 for driving the generator I51 and also the water circulating pump I58 located rearwardly of the generator and on the same driving shaft. It will be noted that the generator and water pump extend longitudinally of the engine between the space provided by a pair of the cylinders such as between cylinders Nos. 4 and 5 as indicated in Fig. 2.

The distributor I59 is mounted near the top of the engine'and has its drive shaft I58 operating in the housing IGI which forms a portion of the casting 68, the shaft I58 having a driving extension I62 which operates in a similar casting housing I53 for driving the lubricating oil pump I54 located at the bottom of the engine.

Shafts I58 and IE2 are driven by a gear I55 secured to shaft I62, this gear meshing with a drive gear I29 as aforesaid.

Before describing further details in connection with accessories mentioned above, it will be noted that the novel sub-assembly including the casting 68 and parts carried thereby is adapted by attachment to the main crankcase casting 25 of the engine as a separate sub-assembly. This sub-assembly includes also the intake manifold, together with fan I53, generator I51, pump I58 and parts associated with these accesssories.

The water pump I58 has a water inlet 155 illustrated in Fig. l, and a delivery outlet I31 illustrated in Fig. 2 for connection through the hose clamping assembly I38 to the inlet 59 for delivering the circulating cooling water to the communicating cylinder jackets 22.

Each of the engine cylinders 2i has mounted by fasteners I19 on the outer ends thereof, a cylinder head I1I providing a combustion chamber I12 and associated spark plug I13. The various cylinder heads I1I are preferably similar in construction, each providing an outwardly opening water jacket I14 communicating with the associated cylinder jacket 22 through the passages I and I16.

The upwardly extending cylinders Nos. 1, 2 and 5 are provided with a cylinder head cover I11, the downwardlyextending cylinders Nos. 3 and 4 being provided with cylinder head covers I18. The covers I11 and I18 are provided with water jackets I19 and I85 respectively communicating with the jackets I14 of their associated cylinder heads IN.

The cover 111 for the uppermost cylinder No. l is provided with a water outlet I8I adapted to return the cooling water from the engine circulating system back to the aforesaid radiator (not shown). The cover I11 for cylinder No. l is provided with the laterally extending conduits I82 and I33, these conduits communicating through the pipes or hose I34 and I85 respectively with the conduits I86 and I81 carried by the covers I11 for cylinders Nos. 2 and 5, respectively. In this manner it will be noted that the cooling water may be circulated through the cylinder jackets 22 outwardly and upwardly for cylinders Nos. 1, 2 and 5, the water circulating through the cylinder heads of these cylinders for distribution through the common outlet I8I either directly upwardly for cylinder No. 1, or through the pipes I84 and I85 respectively for cylinders Nos. 2 and 5.

Cylinders Nos. 3 and 4 are adapted for thermosyphon cooling inasmuch as their covers H8 merely provide closures for the jackets I74 of their respectively associated cylinder heads HI. I have thus provided a novel combination of thermo-syphon and water circulating cooling systems, it being apparent that the hot water from cylinders Nos. 3 and 4 will circulate upwardly for distribution to the outlet I 8!. Furthermore, by providing the cylinder head covers I'll and I18 of relatively different constructions for adaptation to this cooling system, the cylinder heads I'II may all be made as similar casttings thereby simplifying and cheapening the related engine parts.

Referring now to my novel lubricating system, it may be noted first of all that in the illustrated embodiment, my engine is adapted for mounting in the motor vehicle so that the axis of the crankshaft extends rearwardly and downwardly at normally an angle to the horizontal. The extent of this inclination will be apparent from Fig. 1 wherein the bottom surface I85 of the lubricant reservoir or sump I8! is normally adapted to lie horizontal. This reservoir is preferably disposed below the engine and is separated from the valve operating chamber It as well as from the crankcase chamber 20. The reservoir is attached by fasteners I88 to the upper housing member I89 which is clamped by fasteners I99 and plate I9I to the housing structure I92 of the oil pump I64. The oil pump has an inlet conduit I93 terminating in a strainer assembly I94 disposed in the reservoir I81. An oil level gauge I95 has its lower end disposed in the reservoir I81 and is slidable in a housing I96 for convenient withdrawal by an upper handle IiI'I for inspecting the level of the oil in the reservoir.

The lubricating oil is delivered under pressure from pump I64 through the conduits I98 and 895: (see Fig. 12) formed in the rear Wall 69 for delivery to the annular groove 299 in bushings 2t! from whence the oil is radially distributed through a series of passages 202 leading respectively to the valve shaft bearings I8.

Each of the valve shafts, such as the valve shaft 13 illustrated in Fig. 1, has an axial bore 293 supplied by a radial conduit 292 with lubricant by reason of the bushing passage 204, passage 295, and shaft conduit 29B. The lubricant passes forwardly in the shaft bore 293 to lubricate the forward bearing I9 by reason of the radial outlets 297, the forward end of the bore being closed by a plug 298.

The central shaft has an axial lubricant conducting bore 209 supplied from groove 200 by the radial passage 2H], the axial bore 299 extending rearwardly in the disc 83 which is provided with a communicating radial delivery bore 2H for conducting the oil under pressure through the rearwardly opening crank conduit 2 I2 for discharge tothe hollow axial chamber 2I3 of the spindle 4! and the crankpin portion 43 thereof. From the chamber 213 the lubricating oil is conducted through a system of radial passages 2I4 and communicating passages 2I5 in each of the bushings it for lubricating the inner and outer e ring surfaces of these bushings. The lubricant passes rearwardly from chamber 2 I3 to lubricate the rear spindle bearing 42 and radially at 2 it to lubricate the forward bearing 4 I Slidably disposed in the shaft bore 209 is a pressure relief valve 2II urged rearwardly to its limiting position by a spring 2I8 adjustable from the front end of the motor through the adjusting member 2E9 and extension 220 thereof.

The relief valve 2!? has an axial passage 22I for constantly supplying a limited quantity of lubricant forwardly of the valve to the discharge conduit 222 and radially of the valve through passages 223 and 224 to the shaft passage 225 which communicates with the annular chamber 226 of the conduit 22?, the latter in turn comlmunicating with the chamber 228 of the rearward extension housing 229. When the lubricant pressure overbalances the action of spring 2I8 on the relief valve 2H, this valve moves forwardly to directly expose the shaft passage 225 to the shaft conduit 299 thereby delivering the necessary excess quantity of lubricating oil to the outlet passage 225.

The lubricant conduit 222 is adapted to supply 1 to the bearing bushing 239 for the idler gear ihe housing members 227 and 229 are adapted to be fixed to rotate with the shaft 80, these musings being provided with arcuate discharge slots arranged in the various planes containing the cams carried by the valve shafts so that as the shaft rotates, a spray of lubricating oil will be delivered toward the cams and bell crank levers actuated thereby as well as to the inner ends of the tappets and 66 so that all of these operating parts will be thoroughly lubricated. Certain of these arcuate discharge slots are designated 239 and 232*. A further discharge for the rearmost cams is provided by a discharge passage 233 at the rear of the housing member 229.

It will casting 59 will. prevent the passage of the lubricating oil which is thrown around in the valve operating chamber 19 from communicating with the crankcase chamber 29 so that the oil consumption of the engine is materially minimized;

The lubricant which drains downwardly in the valve shaft chamber 19 for collection at the bottom of the chamber and delivery back to the reservoir it? through the opening 234 of casting S3, passage 235 of pump housing I92 and the communicating passage-way 236 provided in the reservoir member I89 and plate I9I.

It being remembered that the engine is adapted to be tilted rearwardly and downwardly during normal conditions, the lubricating oil collected in the main crankcase chamber 29 will drain rearwardly through an opening 23'l, thence rearwardly in the housing 38 for discharge at the rear end thereof through a conduit or pipe 238 which is adapted to communicate with a reservoir I81.

The i bricating oil in the valve chamber and crankcase is thus separated and returned to the reservoir by separate systems.

I have discovered that by locating the lubricant outlet 23% adjacent the periphery of the flywheel 55. the rotation of the flywheel acts as a pump by blowing the oil out of the flywheel chamber and through the outlet pipe 238.

Referring now to my improved intake manifold structure the central manifold portion I45 provides an annular distributing chamber of relatively small diameter in which there is inserted, prior to assembly with the wall member 12, a welded sheet metal assembly 238 adapted to be assembled in a unit. This assembly comprises a.

substantially cylindrical inner distributing conduit 239 having an inlet 240 communicating with the downdraft riser 24! for attachment at 242 with the usual carburetor (not shown).

fhe fuel mixture entering the distributing chamber 239 passes in opposite directions to the outlets 2&3 to a turbulent or mixing chamber 244 whence the fuel mixture reverses its several directions for annular travel through the outer generally annular chamber 245 having the inlets 255. The fuel mixture is distributed from the outer chamber 245 to the various branches M6, the assembly 238 having an outer wall 241 provided with the inwardly extending annular flanges 248 at each inlet to the branches I46 to prevent the wet fuel mixture from directly entering these branches.

Adjacent the outlets 243 of the inner chamber 239, the outer lower wall 249 thereof is provided with grooves 255) tapering jet-like toward the outlets 243 so that the wet fuel entering the inner chamber 239 from riser 24! will follow along the wall 259 for collection in the grooves 249 whence the wet fuel is discharged in the nature of a jet into the chamber 244. Inasmuch as the fuel mixture is directed against itself in two streams at the chamber 244 by reason of the outlets 243, it will be apparent that there will be considerable turbulence in the chamber 244 so that the wet fuel discharged by the grooves 250 will be thrown into the curving fuel mixture stream thereby thoroughly breaking up the wet particles for efficient fuel mixture distribution.

As an additional feature of my improved manifold structure, the manifold wall portion I45 is provided with a relatively small vent l5! which also extends through the adjacent wall of the sheet metal member 238. This vent I5l is located at the bottom of the manifold portion I45 at the mixing chamber 244. When the engine stops running, the residual wet fuel tending to collect at the bottom of chamber 244 will drain by gravity from the manifold through the vent l5 thereby preventing fowling the lowermost cylinders when the engine is started again. When the engine is running, the low pressure in the manifold causes a small jet of air to flow from the atmosphere through vent I5l to impinge on the turbulent mixture at chamber 244 thereby assisting in breaking up the wet fuel at this chamber in the nature of a secondary carburetion.

By reason of my manifold arrangement, I have prevented the formation of wet fuel puddles which have heretofore been carried by the manifold walls directly into one or more of the engine cylinders, usually those extending downwardly, such arrangement heretofore impairing the efficiency of the engine and preventing a smooth idling operation. My invention provides for better distribution of the fuel mixture, smooth idling, and generally improved efficiency of fuel mixture distribution and engine operation.

Various modifications and changes will be apparent from the teachings of my invention, as defined in the appended claims, and it is not my intention to limit my invention to the particular details of construction and mode of operation shown and described for illustrative purposes.

What I claim is:

1. In an engine having a crankshaft and a plurality of cylinders radially disposed around said crankshaft, intake and exhaust valving means associated with each of said cylinders, a plurality of valve operating shafts having their axes parallel to the chankshaft axis, means for driving said shafts from said crankshaft, said shafts being the same in number as the number of said cylinders with one of said shafts associated with each of said cylinders, each of said shafts having cam adapted to close the intake and exhaust valving means of the cylinder associated therewith, a second cam adapted to open the intake valving means of an adjacent cylinder, a third cam adapted to open the exhaust valving means of an adjacent cylinder, and means for operating said valving means includ ing cam followers positioned for operation by a pair of the cams of adjacent shafts.

2. In an engine having a crankshaft and a plurality of cylinders radially disposed around said crankshaft, intake and exhaust valving means associated with each of said cylinders, a plurality-of valve operating shafts having their axes parallel to the crankshaft axis, means for driving said shafts from said crankshaft, said shafts being the same in number as the number of said cylinders with one of said shafts associated with each of said cylinders, each of said shafts having a cam adapted to close the intake and exhaust valving means of the cylinder associated therewith, a second cam adapted to open the intake valving means of an adjacent cylinder, and a third cam adapted to open the exhaust valving means of an adjacent cylinder lying in the opposite direction circumferentially of the crankshaft axis from that of the first said adjacent cylinder, and means for operating said valving means including cam followers positioned for operation by a pair of cams of adjacent shafts.

3. In an engine having a crankshaft and a plurality of cylinders radially disposed around said crankshaft, intake and exhaust valving means associated with each of said cylinders, a plurality of valve operating shafts having their axes parallel to the crankshaft axis, means for driving said shafts from said crankshaft, said shafts being the same in number as the number of said cylinders with one of said shafts associated with each of said cylinders, each of said shafts having a cam adapted to close the intake and exhaust valving means of the cylinder associated therewith, a second cam adapted to open the intake valving means of an adjacent cylinder, and a third cam adapted to open the exhaust valving means of an adjacent cylinder, and means for operating said valving means including a plurality of pairs of levers, each of said levers having an end portion positioned for operation by a pair of cams on two adjacent shafts.

4. In an engine having a crankshaft and a plurality of cylinders radially disposed around said crankshaft, intake and exhaust valving means associated with each of said cylinders, a plurality of valve operating shafts having their axes parallel to the crankshaft axis, means for driving said shafts from said crankshaft, said shafts being the same in number as the number of said cylinders with one of said shafts associated with each of said cylinders, each of said shafts having a cam adapted to close the intake and exhaust valving means of the cylinder associated therewith, a second cam adapted to open the intake valving means of an adjacent cylinder, a third cam adapted to open the exhaust valving means of an adjacent cylinder, means for operating said valving means including a plurality of pairs of levers, each of said levers having an end portion positioned for operation by a pair of cams on two adjacent shafts, and means for mounting the levers of each pair on a common pivotal axis, the pivotal axes of said lever pairs being disposed adjacent the inner ends of said cylinders.

5. In an engine having a crankshaft and a plurality of cylinders radially disposed around the crankshaft axis, intake valving means and exhaust valving means for each of said cylinders, a plurality of valve operating shafts each carrying a plurality of actuators more than two in number, means for driving said shafts from said crankshaft, and means for operating said valving means including a plurality of followers each adapted for operation by a pair of actuators on adjacent valveshafts, one of said actuators of each valveshaft being operatively connected with a pair of said followers.

6. In an engine having a crankshaft and a plurality of cylinders radially disposed around the crankshaft axis, intake valving means and exhaust valving means for each of said cylinders, a plurality of valve operating shafts each carrying a plurality of actuators more than two in number, means for driving said shafts from said crankshaft, and means for operating said valving means including a plurality of followers each adapted for operation by a pair of actuators on adjacent valveshafts, one of said actuators of each valveshaft being operatively connected with a pair of said followers, the remaining actuators of each valveshaft being respectively operatively connected with only one of said followers.

7. In an engine having a crankshaft and a plurality of cylinders radially disposed around the crankshaft axis, each of said cylinders having an intake valve and an exhaust valve associated therewith, each of said valves having cyclical events of opening and closing movements, a plurality of valve operating shafts respectively associated with said cylinders and each having a plurality of cams more than two in number, means for driving said shafts from said crankshaft, and means for operating said valves including a plurality of cam followers each adapted for operation by a pair of cams on adjacent valveshafts, one of said cams of each valveshaft being operatively connected with a pair of said followers for effecting the same cyclical event of the intake and exhaust valves of the cylinder associated with such valveshaft.

8. In an engine having a crankshaft and a plurality of cylinders radially disposed around the crankshaft axis, each of said cylinders having an intake valve and an exhaust valve associated therewith, each of said valves having cyclical events of opening and closing movements, a plurality of valve operating shafts respectively associated with said cylinders and each having a plurality of cams more than two in number, means for driving said shafts from said crankshaft, and means for operating said valves including a plurality of cam followers each adapted for operation by a pair of cams on adjacent valveshafts, one of said cams of each valveshaft being operatively connected with a pair of said followers for effecting the same cyclical event of the intake and exhaust valves of the cylinder associated with such valveshaft, the remaining I cams of each valveshaft being respectively operatively connected with only one of said followers for effecting the other of said cyclical events for a valve of a pair of cylinders adjacent the cylinder associated with such valveshaft.

9. In an engine having a crankshaft and a plurality of cylinders radially disposed about said crankshaft, valving means associated with each of said cylinders, a plurality of valve operating shafts having their axes parallel to the crankshaft axis, a driving pinion co-axial with the axis of said crankshaft and driven therefrom at the same speed, a gear mounted on one of said. valveshafts and meshing with said pinion for transmitting a reduction drive to the last said valveshaft, each of said valveshafts having a gear drivingly connected thereto, and an idler gear coaxial with the axis of said crankshaft and meshing with the last said valveshaft gears whereby to drive said valveshafts in unison from said crankshaft.

10. In an engine having a crankshaft and a plurality of cylinders radially disposed about said crankshaft, valving means associated with each of said cylinders, a plurality of valve operating shafts having their axes parallel to the crankshaft axis, said valveshafts being equal in number to the number of engine cylinders and being disposed around said crankshaft axis at substantially equal distances therefrom, means for driving oneof said valveshafts at a reduced speed from said crankshaft, and means for driving the remainder of said valveshafts in unison with said crankshaft driven valveshaft.

11. In a radial engine having a crankshaft provided with a cantilever crank pin, engine valve operating means adapted to be driven from said crank pin, and means for driving said valve operating means including a roller connection between said crank pin and said valve operating means, said connection being adapted to accommodate deflection of said crank pin relative to said valve operating means connected thereto.

12. In an engine driving mechanism, a rotatable shaft having a driving cantilever crank, a member rotatable on an axis coaxial with that of the crankshaft and adapted to be driven from said crank, a pin carried by said member and disposed in telescopic relation with said crank along the axis thereof, said pin having a clearance radially with respect to said crank to accommodate relative radial deflection of said crank and pin, and a rotatable drive transmitting cylinder intermediate said crank and pin.

13. In an engine of the radial cylinder type, a crankshaft rotatable about an axis around which said cylinders radiate, a plurality of valveshafts having their axes parallel to said crankshaft axis and spaced around said axis, an annular intake manifold disposed adjacent one end of said engine in close proximity to one end of said valveshafts, said intake manifold having branches respectively leading to said cylinders, said intake manifold having an annular wall-forming member thereof provided with a plurality of bearings respectively journalling said valveshaft ends.

14. In an engine of the radial cylinder type, a unitary crankcase structure having a centrally disposed crank-receiving chamber and a plurality of cylinders disposed radially around said crank-receiving chamber, a crank journalled in said crankcase structure for operation in said crank-receiving chamber, valving means associated with each of said cylinders, a sub-assembly adapted for attachment to said crankcase structure for operating said valving means, said subassembly including a unitary chamber-forming structure having a plurality of pairs of axially aligned bearings extending longitudinally of the engine, a camshaft journalled in each of said pairs of bearings and having their axes disposed substantially parallel with the axis of rotation of said crank, said chamber-forming structure having an outwardly extending cam follower guide associated with the valving means of each of said cylinders, each of said guides having a support bracket projecting therefrom, and fasteners removably securing said brackets to said cylinders respectively.

15. In an engine, a unitary crankcase structure having a centrally disposed crank-receiving chamber and a plurality of cylinders disposed radially around said crank receiving chamber, successive cylinders having their axes progressively relatively offset longitudinally of the engine, a crank journalled in said crankcase structure for operation in said crank-receiving chamber, valvingmeans associated with each of said cylinders, a sub-assembly structure adapted for attachment to said crankcase structure for operating said valving means, said sub-assembly structure providing a chamber adapted to receive valve operating means, means for operating said valving means operably disposed in said sub-assembly chamber, said crankcase structure and said sub-assembly structure having complementary sealing surfaces inclined at an angle relative to a plane perpendicular to the axis of rotation of said crank, and means for removably attaching said sub-assembly structure to said crankcase structure.

16. In a valve operating mechanism, a valve, an actuator, means for vibrating the actuator, a follower adapted for movement by the actuator to open and close the valve, means operably connecting the follower and valve, said actuator and follower having engaged bearing surfaces so constructed and arranged that their area of engagement is substantially greater when said valve is operated to its extreme positions of opening and closing movements than when said valve is operated to substantially its mid-position of movement.

1'7. In a positive valve operating mechanism,

an actuating lever, a valve operating tappet op erably engaging said lever, means for oscillating said lever about an axis of pivotal support, means for guiding said tappet for reciprocating movement imparted thereto by said lever, said tappet having a substantially spherical surface, said lever having a pair of substantially spherical surfaces respectively engaging said tappet surface approximately at the opposite limits of oscillatory movement of said lever.

18. In a positive valve operating mechanism. an actuating lever, avalve operating tappet operably engaging said lever, means for oscillating said lever about an axis of pivotal support, means for guiding said tappet for reciprocating movement imparted thereto by said lever, said tappet having a substantially spherical surface, said 1ever having a pair of substantially spherical surfaces respectively engaging said tappet surface approximately at the opposite limits of oscillatory movement of said lever, said lever having a surface portion intermediate said pair of surfaces adapted for engagement with said tappet surface when said lever'is operated at substantially its mid-position of oscillatory movement.

19. In a positive valve operating mechanism, an actuating lever, a valve operating tappet operably engaging said lever, means for oscillating said lever about an axis of pivotal support, means for guiding said tappet for reciprocating movement impart-ed thereto by said lever, said tappet having a pair of oppositely curving substantially spherical surfaces spaced apart to receive one end of said lever, said lever end having two pairs of approximately spherical surfaces, one of said lever surfaces of each pair being respectively engaged with said tappet surfaces when said lever is oscillated to substantially its limit of travel in one direction of its movement, the other of said lever surfaces of each pair being respectively engaged with said tappet surfaces when said lever is oscillated to substantially its limit of travel in the other direction of its movement.

ROGER K. LEE. 

